This summer, I had the pleasure of having coffee in Palo Alto with Eva. She had been to the Exploratorium the day before, where, in the gift shop, she picked up a couple cool science books for the sprogs. “Of course, you’ll have to blog them!” she said.

This book isn’t a biography of Louis Pasteur. Instead, it’s a discussion of what he discovered and (more importantly, from the point of view of the Free-Ride offspring) how he discovered it.

We start with a glimpse of life in the mid-1800s, when the guy who milks the cow coughs into his hands and then sets about the task of milking without stopping to wash those hands.

Hands which the sprogs would call “germy” but which people at the time would not, since no one knew that germs caused disease.

The elder Free-Ride offspring was actually a little surprised that in those times scientists had already seen germs through microscopes. It’s just that no one knew what those microorganisms did. (People also weren’t clear on where microorganisms came from, but we’ll get to that in a moment.) And, knowing that germs existed wasn’t really enough to keep people (especially non-scientists) from spreading them, which meant that your morning milk could be a good source of calcium and tuberculosis.

When Pasteur enters the story, he’s not focused on milk but on wine. He was asked to solve the mystery of why some batches of wine went bad. A peek under the microscope showed the good wine to be populated by yeast and the bad wine to have some yeasts and a lot of rod-shaped microorganisms. The winemaker was happy to have a way to tell good wine from bad before selling it, but Pasteur wanted to know more.

It turns out that people in the mid-1800s thought that yeast was a product of wine fermentation rather than an ingredient required to make things ferment. Pasteur sets up a nice experiment with water, sugar, yeast, and nitrogen in sealed flasks to see which of these ingredients was necessary for fermentation. (He used four flasks; you can probably figure out how he had to set them up to answer the question.)

After he learned all kinds of nice things about yeast, he figured out that those rod-shaped microorganisms in the bad wine were the same ones that can be found in spoiled milk. (As it happens, we are using the same kind of lactic acid producing bacteria right now to pickle slices of daikon radishes.)

The next challenge was figuring out how to get rid of the unwanted microorganisms.

The book goes on to describe Pasteur’s experiments in developing a process (Pasteurization) that would kill the bad bacteria without spoiling the taste of the wine. It also discusses the experiments Pasteur performed to demonstrate that microorganisms are not the product of spontaneous generation, but are kicking around in the air we breathe (and into which we sneeze).

The elder Free-Ride offspring was taken by the fact that, after Pasteur’s discoveries, city dairies started offering a service where you could bring in your raw milk to get it pasteurized. Another surprise was that these experiments were not originally driven by an effort to stop the spread of disease, but to an effort not to sell bad wine.

I pondered whether these experiments would ever have been done in the first place if microorganisms didn’t make things taste different. Some of the microorganisms featured in the story — like the germ that causes tuberculosis — apparently didn’t make the milk taste any different at all.

This isn’t really a little-kid book, but the comic book style of presentation will grab middle-grades grade school kid. The discussions of Pasteur’s methodological experiments are especially nice.

Finally, the younger Free-Ride would like to contribute a related joke:

They had a bunch of other science-related graphic novels as well. I forgot which scientists/discoveries those were about, but this was the one that seemed like it would have been the most interesting story. (And I also picked it for the cover. Pasteur looks like a superhero!)

Pasteur also did a lot of work on the role of yeast in brewing beer and of other microorganisms in spoiling it, in a patriotic quest to turn science to the purpose of making French beer the equal of German.

This was not forgotten by brewers. Some years ago I picked up a copy of Vallery-Radot’s Life of Pasteur at an auction. The imprint on the cover showed that it had been a gift to the attendees at the convention of a national brewer’s organization in 1934.

“This was not forgotten by brewers. Some years ago I picked up a copy of Vallery-Radot’s Life of Pasteur at an auction. The imprint on the cover showed that it had been a gift to the attendees at the convention of a national brewer’s organization in 1934″

Oh you’d better believe it! If it wasn’t for Pasteur, we wouldn’t know about them lovely yeast cells, and even more importantly (from a brewers prospective) that they make the tasty alcohol, and that you can make pure strains to control what esters, phenols and other by-products of fermentation end up in your final product (OK that wasn’t his discovery per se, but he got the ball rolling) !

I think Feynman’s wife (1st) got her TB from unpasteurized milk – in a compedium of his writings, a footnote indicated the lesions similar to hers had occurred to a reader and his sister, who were treated for TB which they had gotten from raw milk sold by a neighbor.

An interesting side effect of Pasteur having done his work for the wine industry is one of the more outlandish arguments used by germ theory deniers — they present his role as part of some conspiracy to make bad product look good, or get people drunk, or something like that. It would seem that many germ theory deniers have a nasty neo-Prohibitionist streak and use that to cast Pasteur as a bad guy.

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